1. Field of the Invention
This invention relates to a control system, a power supply device, a device unit, an image pickup system, etc., in which a plurality of device units such as an image pickup unit, etc., are removably attached for use to a control device.
2. Description of the Related Art
Computers of the kind having connection terminals such as PCMCIA slots are generally arranged to use card-shaped device units arranged to function differently as a facsimile, memories, etc., with these device units inserted into the connection terminals. The connection terminals are arranged not to limit the usable device units. The operator of such a computer is, therefore, allowed to select any of such card-shaped device units having a desired function. FIG. 1 shows by way of example an image pickup system including a computer and an image pickup unit removably attachable to the computer. The image pickup system is described by way of example as follows.
Referring to FIG. 1, the image pickup system includes an image pickup unit (camera unit) 23 which is formed in a card-like shape, a computer 25 and a connection terminal 26 provided for connecting the image pickup unit 23 to the computer 25.
The image pickup system picks up an image by means of an optical system and a CCD which are disposed within the image pickup unit 23. The image picked up is converted into digital data. The picked-up image data is transferred via the connection terminal 26 to the computer 25. The computer 25 contains therein a display device and a recording device. The picked-up image data from the image pickup unit 23 is displayed and recorded by the computer 25.
In the image pickup system shown in FIG. 1, the computer 25 has another connection terminal 27. A device unit 24 having a function which differs from the function of the image pickup unit 23 is connected to the connection terminal 27, which is arranged to function in the same manner as the connection terminal 26. Any device unit that can be connected to one of the connection terminals 26 and 27 is connectable also to the other connection terminal.
The device unit 24 is, for example, arranged to function as a facsimile (hereinafter referred to as a fax card). With the fax card 24 connected to the connection terminal 27, the picked-up image data recorded within the computer 25 is transmitted. The computer 25 controls the image pickup unit 23 and the fax card 24 which are respectively connected to the connection terminals 26 and 27 and, at the same time, also supplies electric power to them.
The image pickup system shown in FIG. 1 which is configured as described above is capable of performing an image pickup action, recording and displaying the picked-up image data and, with the fax card 24 connected to the computer 25, transmitting the picked-up image data. In a case where the image pickup unit 23 or the fax card 24 is not used, it may be used for some other apparatuses by detaching it from the connection terminal 26 or 27.
The method employed for the above-stated system, however, has presented the following problem.
The computer 25 constantly supplies electric power to the connected device units irrespectively of the operating or nonoperating state of the device units. Accordingly, even when only the fax card 24 is being used while the image pickup unit 23 is also attached to the computer 25 but is not being used, the computer 25 supplies electric power also to the image pickup unit 23, so that electric power is wasted. Alternatively, even when only the image pickup unit 23 is being used with the fax card 24 not being used, the computer 25 supplies electric power also to the fax card 24, so that electric power is wasted.
In cases where the computer 25 is arranged to be driven by the electric energy of a power source of a limited capacity such as a battery or the like, the amount of electric power consumed by the device units connected to the connection terminals of the computer 25 presents a serious problem. When a total of electric power consumed by the device units connected to the computer 25 is larger than the amount of electric power which can be supplied from the computer 25, one of or all of the device units connected to the computer 25 become inoperative or the computer 25 might come to malfunction. Such a malfunction has often caused the image pickup system to stop operating.
Further, in cases where an image pickup action is a primary function, electric power tends to be consumed so much by the fax card 24 to prevent adequate fulfillment of the image pickup action. In such a case, it has been necessary either to remove the fax card 24 from the computer 25 or to manually cut off the supply of electric power to the fax card 24.
Further, the image pickup system and an image signal processing device related thereto have presented the following problems.
There has been no means for enabling the operator of the image pickup system or the computer to confirm the connected state of the image pickup unit. Therefore, if a program of control over the image pickup unit happens to be executed in a state of having the image pickup unit not adequately connected to the computer, either the program or the computer might malfunction to necessitate a long period of time before resumption of its normal state.
Further, with the computer having a plurality of connection terminals, if the connection terminal to which the image pickup unit is connectable is limited among the plurality of connection terminals, there is a probability that the image pickup unit will be connected to a wrong connection terminal.
Further, there has been no means for enabling the operator of the image pickup system or the computer to confirm the operating state of the image pickup unit. Therefore, if the picked-up image data is not monitored by means of a display device contained in the computer, it has been impossible to confirm the operating state of the image pickup unit. Even in a case where the picked-up image data is arranged to be monitored, it has been sometimes hardly possible to intuitionally know the data of operation such as the image pickup speed of the image pickup unit and the number of colors in use, etc.
Further, the image pickup system has been provided with no means for enabling the operator of the image pickup system to know the pickup conditions under which previous image data has been obtained.
Further, in a case where the image pickup unit has a lens cover, the opened or closed state of the lens cover has nothing to do with the operation of the image pickup unit. In such a case, the lens cover has necessitated the operator of the image pickup system to close the lens cover when the image pickup unit is not used. Besides, it has sometimes happened that the operator of the image pickup system inadvertently operates the image pickup unit with the lens cover left closed.